critical speed is determined based on how sharp the curve is how much bank is in the roadway and the road surface’s “stickiness” or coefficient of friction. by measuring these three factors and plugging them into a formula the critical speed of a curve can be calculated. let’s examine a curve in the road that has a radius of 200 feet
some progress has been made by engineers in understanding the severe limitations to the above 'critical speed in a curve' formula since my 1984 nafe paper 'critical speed in a curve'. that paper examined one reason why the derivation of the equation is too simplified to be accurate in most cases where it is used.
critical speed yaw test cont’d • a radius was calculated for each chord • if the vehicle is in a true critical speed yaw there should be a reduction in speed from the first radius to the second radius. • we will calculate the speeds using the standard critical speed yaw equation and the drag factor from the taurus which was a non-abs
and the speed is referred to as the critical speed v c. equation 4 with an equal sign is often referred to as the critical speed formula as used in the field accident reconstruction and written as: v c = %&&&f g r = %&&&15f r (5) the first form of eq 5 is valid for any consistent set of units; the second gives a speed of miles per hour if r is
the critical speed for a horizontal roadway curve critical speed used in this context is a term for the speed at which a vehicle will lose lateral control on a given roadway curve. the normally flawed procedure is to assume the highway curve radius as the critical path taken by the vehicle.